You have to press OK to get the WSDL location to be accepted.
Should use "key-pressed" listener to catch the event and close the dialog if "return" key is pressed.
Also fixed this for auto generated dialogs like Add Soaplab and Add Biomart that use uibuilder in activity-palette-ui.
Integrated in net.sf.taverna.t2.ui-activities #1419
Integrated in net.sf.taverna.t2.ui-components #1232
works for WSDL, Soaplab and BioMart.
BioMoby one (which is custom) does not work, but it also have more than 1 field to fill in.